<!DOCTYPE html>
<html>

<head>
	<meta charset="utf-8">
    <script>
    var txt = "";

    function message() {
        try {
            adddlert("Welcome guest!");
        } catch (err) {
            txt = "本页有一个错误。\n\n";
            txt += "错误描述：" + err.message + "\n\n";
            txt += "点击确定继续。\n\n";
            alert(txt);
        }
    }
    </script>
</head>

<body>
    <input type="button" value="查看消息" onclick="message()" />
</body>

</html>
